Question

log(tan 5) + log (tan 25) + log (tan 65) + log (tan 85) =?

Answer 1

log( tan5) + log( tan25) + Iog( tan65) + log( tan85)

[ use, logm + logn = logmn ]

= log{ tan5 .tan25 . tan65° . tan85° }

= log{ tan( 90-85) .tan(90-65).tan65.tan85}

= log{ cot85. cot65°.tan65°.tan85°}

= log{ ( tan85°.cot85°).( tan65°.cot65°)}

= log{ 1 × 1 } = log(1 )

= 0

Answer 2

Answer:

answer is 0

option a

thank you